RPN Research has developed a new medical device, the Bioelectric Field Imager (BFI) which can measure the electric field in human skin non-invasively. The hand-held BFI scans a vibrating sensor over the skin without making contact with it and plots the surface potential distribution over a 1 cm distance in about 1 minute. Using a table-mounted version of this new imager in Phase I of this project, we have revealed for the first time that malignant melanomas in mice generate an electric field that can be easily detected by the BFI. These studies found that the electric field can be detected as early as one day after injection of the melanoma cells and the electric field strength is proportional to both the size and growth rate of the melanoma. We have also completed a Phase I Clinical Trial using the hand-held BFI to measure the electric field in both benign and malignant human skin lesions and have found that malignant basal and squamous cell carcinomas generate large electric fields in human skin as well. In our Clinical Trial we found that the hand-held BFI detected an electric field averaging 696 mV/mm at the borders of three of the four malignant lesions in the study (3 basal cell carcinomas and 1 squamous cell carcinoma). This 75% reliability rate in our first human clinical trial is encouraging. In addition, the average electric field measured near benign lesions (223 mV/mm) was only one-third the size of those near malignant lesions, making it very easy to distinguish between the two. In 9 out of 13 benign lesions (70%) we detected a very small electric field and correctly predicted in a blinded study they were not malignant. During this Phase II SBIR we will refine the design of the hand-held BFI to make it more versatile and reliable for human use my making it lighter, wireless and compatible with a wider variety of lesion shapes. We will complete a Phase II Clinical Trial with at least 300 patients to establish the reliability of this new instrument for rapidly distinguishing malignant from benign skin lesions. We will also compare the electric field near melanomas as measured with the BFI to that measured using conventional microelectrodes to both serve as a confirmation of the accuracy of the BFI and to further demonstrate its advantages over the direct contact measurement approach. If the handheld BFI is able to reliably detect malignant skin lesions, it will improve the quality of life for tens of thousands of dermatology patients in the United States alone. [unreadable] [unreadable] [unreadable]